Aryl mercury acid salts and method of preparation thereof



United States Patent ARYL MERCURY ACID SALTS AND METHOD PREPARATION THEREOF No Drawing. Application April 1, 1957 Serial No. 649,625

19 Claims. (Cl. 16730) This invention relates to aryl mercury acid salts of weak organic acids, and more particularly to aryl mercury acid salts of naphthenic and fatty acids obtained in the form of oils that are useful as fungicides, bactericides, mildew proofing agents, and for other antimicro-organismal purposes.

, Normal aryl mercury salts of organic acids are well known for their bactericidal and fungicidal properties. Such salts contain one equivalent of the organic acid :ani'on attached to an aryl-mercury group, and they are obtained as solids, semi-solid curds, or in the form of very viscous oils. In order to utilize these compounds commercially as bactericides, they are dissolved in organic solvents. United States Patent No. 2,177,049 gives examples of the preparation of solid normal aryl mercury salts in which an organic acid is reacted with an aromatic mercury salt of an acid weaker than the reacting organic acid.

Also, aryl polymercury naphthenates containing from two to fiveI-lg-naphthenate groups attached to the aryl ring have been employed as toxicants. For example,

United States Patent No. 2,423,044 discloses the preparation of aryl polymercury naphthenates by non aqueous reactions followed by extraction of the polymercury naphthenate from the reaction mixture by immiscible solvents. Such compounds also are dissolved inorganic solvents for application as anti-microbials.

In accordance with this invention and as a brief summary thereof, aryl mercury compounds that are at least slightly water soluble are reacted with more than 1.2 equivalents of a compound selected from the group consisting of naphthenic acid, sodium naphthenate, potassium naphthenate, ammonium naphthenate, fatty acids, sodium salts of fatty acids, potassium salts of fatty acids, ammonium salts of fatty acids, and mixtures of such compounds. When the acid concentration of the resultant reaction product is maintained between about pH 3 and pH 7, a distinct fluid oily layer containing an aryl mercury acid salt is formed that, unlike the previous aryl mercury compounds, does not require solvent extraction for its isolation and is readily dispersible in either water or oil systems for use as a fungicide and bactericide.

Aryl mercury acid salts prepared by the method hereof contain an additional equivalent of naphthenic acid or a fatty acid attached to the aryl mercury salt, thereby forming distinct and stable aryl mercury acid salts. Such compounds are clearly distinguishable in both properties and structure from the prior normal aryl mercury salts of organic acids because of the additional acid present in the aryl mercury acid salts. Furthermore, in the method hereof the reacting aryl mercury salts are salts of acids stronger than the naphthenic or fatty acid anions with which they react, and this is directly contrary to the procedure disclosed in the aforementioned Patent No. 2,177,049.

In greater detail, any aryl mercury compound that is ice 1?. at least slightly water soluble may be employed as a reactant. Such aryl mercury compounds may be described by the formula Ar-HgX in which the aryl is a substituted or unsubstituted aryl radical, such as phenyl, tolyl, chlorophenyl, tertiary butyl phenyl or naphthyl. The Hg represents mercury, and the X is any anion which will impart at least slight solubility to the compound, such as acetate, propionate, hydroxide, borate, nitrate (basic), lactate and benzoate. Phenyl mercuric acetate, phenyl mercuric borate and tolyl mercuric hydroxide are examples of particularly suitable aryl mercury compounds, and they are readily available commercially.

For practical purposes, the aryl mercury compound should have a solubility of at least 0.01% at 20 C. and preferably a solubility of above 0.1%. With solubilities below 0.01% the reaction proceeds very slowly. Since phenyl mercury acetate has a water solubility of 0.47% and phenyl mercury borate has a solubility of 1.09%, it is apparent that such compounds are well above the minimum desired solubility.

The aryl mercury compounds are reacted with a compound selected from the group consisting of naphthenic acid, sodium naphthenate, potassium naphthenate, ammonium naphthenate, fatty acids, sodium salts of fatty acids, potassium salts of fatty acids, ammonium salts of fatty acids, and mixtures of such compounds. All of such naphthenic or fatty acid compounds are either in liquid form or are water soluble salts, and thus are in a reactive form.

Naphthenic acid as employed herein refers to naphthenic acid obtained from petroleum, or in other words monocarboxylic acids derived from petroleum having the general composition of R(CH ),,COOH, in which R is predominately an alkylated cyclopentane or bicyclopentane group, with the carboxyl group located on a side chain. carboxylic acid compounds in minor proportions. Naphthenic acid is well'known, and it may easily be converted into a salt by neutralization with a base such as sodium hydroxide, potassium hydroxide, or ammonium hydroxide.

Fatty acids which may be reacted with the aryl mercury compound to produce the aryl mercury acid salts hereof contain between about 8 and 18 carbon atoms. They may be saturated or unsaturated, straight or branched chain fatty acids. For example, oleic acid, stearic acid, 2-ethyl hexoic acid, or linoleic acid may be utilized. If more than 18 carbon atoms are present in the chain, the final product tends to be a solid, whereas a fatty acid having less than 8 carbon atoms tends to produce a final product that is highly dispersed and does not form the desired separate oily layer. Such acids likewise are readily available commercially, and if desired they may be neutralized with sodium, potassium or ammonium hydroxides before or during the reaction with thearyl mercury compound. The naphthenic acid compound or the fatty acid compound may be employed entirely in the form of the sodium, potassium or ammonium salt or as the acid itself. Also, mixtures of any of such compounds may be utilized, or more than one of such compounds can be added to the aryl mercury compound separately. It has been found that even mixtures of the naphthenic acid compounds with the fatty acid compounds may be employed.

The reaction is most advantageously carried out by employing an aqueous slurry of the aryl mercury compound. Ihis insures that a saturated solution of'the compound will be present together with an excess of the undissolved aryl mercury compound. Although it is not necessary to conduct the reaction in an aqueous medium since the aryl mercury compound will react with the naph- Such acids may also contain cyclohexane 3. thenic and fatty acid compounds in the anhydrous state, best yields and most rapid reactions are obtained when naphthenic or fatty acid compounds are added to an aqueous slurry of the aryl mercury compound. Also, for practical purposes concentrations of at least 10% by Weight of the reactants are employed in the aqueous slurry so that a sufiicicntly large yield of the reaction product will be obtained.

It has been found that the conditions under which the aryl mercury compound will react with the naphthenic or fatty acid compounds are not very critical, and that such compounds are surprisingly reactive. For example, the reaction is preferably conducted at a pH greater than 6 since the new compound hereof is formed most rapidly under alkaline conditions. However, the reaction will proceed even at a pH below 3. Also, the reaction is advantageously carried out at temperatures between 60 C. and 100 C. in order to increase the reaction rates. Nevertheless, the reaction between the aryl mercury compound and the specified naphthenic or fatty acid compound occurs at room temperatures, although not as rapidly as at the elevated temperatures. In order to further increase the rate of reaction, the reaction mixture is desirably agitated during addition of one reactant to the other. Preferably, the acid compound is added to the slurry of aryl mercury compound, but the opposite procedure may be followed.

As the naphthenic or fatty acid compound is added to the slurry, a solid or very viscous oil is produced which corresponds to the normal aryl mercury salt formed by reaction of one equivalent of the naphthenic or fatty acid compound with one equivalent of the aryl mercury compound. However, when the amount of the naphthenic or fatty acid compound is increased to 1.2 equivalents and above per equivalent of aryl mercury compound, the viscosity of the product drops rapidly evidencing formation of a new compound. This viscosity drop is in marked contrast to the gradual slope of a viscosity curve when non-reacting blends are intermixed.

The fiuidizing effect obtained by adding additional naphthenic or fatty acid compound produces a reaction product that is partially dispersed in an alkaline reaction medium. However. a distinct oily layer of the aryl mercury acid salt is formed when the pH of the reaction mixture is between about 3 and 7, such as when naphthenic or fatty acid is used without the addition of a base. With a basic reaction mixture, the mixture is acidified whereupon it forms a desired distinct separate oily layer. The added acid breaks the dispersion and provides a distinct oily layer that may readily be separated from the remainder of the reaction mixture by any suitable mechanical means, such as by a separatory funnel arrangement. Preferably, a weak acid that does not form insoluble reaction products is utilized for adjusting the pH of the reaction mixture to between about 3 and 7. For example, acetic acid is suitable for this purpose. The desired oily separate layer of the reaction product is obtained only when more than 1.2 equivalents of the naphthenic or fatty acid have been added per equivalent of aryl mercury compound. Substantially theoretical yields of the aryl mercury acid product hereof are obtained.

The oily layer of the reaction product is a complex having the following formula: ArHg-A.n(HA) in which Ar is.a substituted or unsubstituted aryl group such as phenyl, tolyl, chlorophenyl, tertiary butyl phenyl and naphthyl; Hg is mercury; and A is the anion of a weak monobasic acid selected from the group consisting of naphthenic acid, fatty acids containing between 8 and 18 carbon atoms, and mixtures of such naphthenic or fatty acids. The dot between the A and the n represents a bond between the normal aryl mercury salt and the naphthenic or fatty acid, and n is the number of moles of the acid above that required to form the normal aryl 4 mercury salt of the acid, the value of which may be 0.2 or higher, and H is hydrogen.

The bactericides and fungicides hereof have a value of 11 greater than 0.2. At lower values of n, the product is in the form of a very viscous oil, semi-solid curds or a solid compound which is not readily dispersible in aqueous and oil systems in accordance with the method of the present invention. The viscosity of the product drops rapidly as the value of n is increased above 0.2 due to the formation of increasing amounts of the aryl mercury acid compound. When n is equal to 1.0, the entire aryl mercury compound has been converted into an aryl mercury acid compound. Consequently, best results are obtained when n is about 1.0 since this represents the pure compound hereof. Even higher values of n may be used since they provide an oily composition containing the pure aryl mercury acid compound. Nevertheless, values of n down to 0.2 provide products that are readily dispersible in oil and water systems and which are excellent bactericides and fungicides.

Viscosity curves and infrared data indicate clearly that a distinct compound is formed which contains the acid bonded to the normal compound by means of hydrogen bonding. For example, infrared examination of naphthenic acid shows that it is present in the form of a dimer in which the two acid groups are bonded by hydrogen bonding. This pure compound contains a characteristic infrared absorption band at 10.65 microns which establishes hydrogen bonding. It also shows a band at 5.84 microns to indicate the presence of a normal C=O bond. Infrared tests of normal phenyl mercuric naphthenate disclose ion pair bonding between the mercury and the oxygen atom as indicated by an absorption band at 6.35 microns, but the normal C==O bond is not shown. However, in pure phenyl mercury acid naphthenate in which n=1 in the foregoing formula, an absorption band is shown for the resonating carboxylate ion similar to the normal salt, but it is shifted approximately 0.1 micron to 6.23 microns. The significance of this shift is that, While the HgO b nd is still ionic, it is infiuenced by combination with the second equivalent of naphthenic acid through hydrogen bonding of the latter to the carboxylate ion of the normal mercury salt.

The most important fact disclosed by the infrared absorption curves is that there is no free naphthenic acid present in the product when 21:1, because the characteristic band for the free naphthenic acid at 10.65 microns is not present. The absence of naphthenic acid definitely establishes that an aryl mercury acid compound, which may be called a complex, has been formed in which the second equivalent of the acid is taken up by hydrogen bonding to the carboxylate ion of the normal phenyl mercury salt.

The products of this invention in which n is greater than 0.2 may be used directly in the form of oils, and they are dispersible in both oil and water systems. However, such products are preferably mixed with from about 5 to 10 percent by weight of ammonium hydroxide based on the weight of the acid naphthenate. Heat is evolved in this reaction with ammonia, and the resultant product is more readily dispersible in both oil and water systems than the pure aryl mercury acid salt. Also, the aryl mercury acid salts are miscible with formamide in the presence of ammonia, and with dimethyl formamide with or without ammonia, to form more readily dispersible products for practical use. Other strong organic solvents miscible in oils and water, such as low molecular weight alcohols, and non-ionic dispersing agents such as polyoxyethylene condensation products of octyl phenol may also be mixed advantageously with the aryl mercury acid salts.

Either the aryl mercury acid salt reaction products or such salts mixed with the dispersing aids described above are applicable to all anti-microbial uses of the aryl mercury compounds of the prior art. For example, they are valuable as preservatives for pigment pastes, water based paints and oil based paints. In paint use the preservative action is effective in both the storage container and the finished paint film. Also, the products hereof are useful in paint vehicles which may be subject to bactericidal or fungal deterioration, and in marine paints to prevent growth of weeds, algae, barnacles and action of attacking organisms. Other uses for such compounds include addition to the heater in the manufacture of paper to prevent deterioration produced by bacteria and fungi, and as seed disinfectants to prevent mold growth.

One of the important advantages of the method hereof is the ease of isolating the separate distinct oily layer of the product by mechanical separation. Also, the compounds hereof in which n is greater than 0.2 are readily dispersible and thus highly effective in both water and oil systems, whereas compounds such as the normal aryl mercury naphthenate are suitable only for oil systems.

- The high fungistatic and fungicidal power of the phenyl mercuric acid preparations hereof is illustrated by the standard tests summarized in Table I. These tests were carried out by making dilutions of the preparations in sterile distilled water, and using polyoxyethylene sorbitan monoleate, a non-ionic surface active agent, sold 'by Atlas Powder Company under the trademark Tween 80, as an emulsifying aid for the fungicidal tests. Dilutions for the fungistatic tests were prepared in dextrose peptone broth. The culture of Aspergillus niger used in the tests was isolated from canvas which had become infected naphthenate, when addedto the dispersion, will completely prevent the growth of the organisms and the consequent deterioration of the product.

:The following are typical examples of the preparation of aryl mercury acid salts of naphthenic and fatty acids:

Example 1 In a stainless steel reaction vessel 300 lbs. (0.894 lb.- mol) of phenyl mecuric acetate crystals (technical grade) were slurried in 4890 lbs. of water containing 36 lbs. (0.438 1b.-mol)v of 50% sodium hydroxide solution and heated to 80 C. The resulting suspension containingspartially dissolved phenyl mercuric acetate had a pH of .9.

Solutions of sodium and ammonium naphthenate salts were prepared as follows:

Sodium soap258 lbs. of naphthenic acid (1.072 lb.- mols) were stirred into 873 lbs. water containing 90 lbs. of 50% sodium hydroxide solution (1.098 lb.-mols) giving a sodium naphthenate solution of 23% concentration.

Ammonium soap228 lbs. of naphthenic acid (0.938 lb.-mol) were stirred into 873 lbs. water containing 59 lbs. of concentrated ammonium hydroxide (28% NH (0.974 lb.-mol) giving an ammonium naphthenate solution of 23% concentration.

The sodium naphthenate solution was then added slowly with good agitation to the phenyl mercuric acetate slurry maintained at 80 C. A heavy oil phase separated as with mildew. 30 large viscous globules intermixed with a concentrated TABLE I Mercury Content, Dilution Dilution Sample Compound and Method of Additives in Samples Percent Inhibiting Killing Preparation y Growth of A. m'qcr Weight A. m'uer a Phenyl mercury acid naphthenate NH; and non-ionic agent 20. 2 1:200, 000 1:900

prepared in accordance with Example 1 hereof. b Same as a 21. 5 1:200, 000 1:925 c Phenyl mercuric acid naphthenate 23. 0 1:250, 000 1 :976

prepared in accordance with Example 4a hereof. Same as c Dimethyl Formamide and 19. 6 1:200, 000 1:900

non-ionic agent. Same as c NH: and non-ionic agent... 19. 7 1:200, 000 1:900

Furthermore, certain pigment color dispersions are very sensitive to microbial infection. Practical usage has shown very superior performance of the phenyl mercuric acid naphthenate hereof, as compared with fungicides such as phenyl mercuric acetate, potassium orthophenyl phenate, and mixtures of the two, in preserving various pigment color dispersions against deterioration caused by bacterial and fungal organisms.

.The test method used to control this application of phenyl mercuric acid naphthenate preservative for pigment dispersions is carried out as follows: A standard P. D. A. (peptone dextrose agar) nutrient is placed in a Petri dish and streaked with the sample under test. The dish is then incubated 24 hours. If no growth of fungus is visible, the sample is inoculated with a culture of the troublesome organisms taken from a spoiled batch of the product. After this inoculation of the sample, incubation period and Petri dish test are repeated a second and a third time. If the growth of fungus is negative after the last inoculation, the result is taken as conclusive and the sample is considered safe enough to withstand normal usage without spoilage. This test has been satisfactorily supported by performance data in actual practice for a substantial period.

With those pigment color dispersions which may be particularly troublesome in regard to spoilage by molds and bacteria it has been found that as little as 0.07 percent mercury in the form of phenyl mercuric acid emulsion. The pH of the mixture at this stage was 10.0.

The ammonium naphthenate solution was next added in the same manner, maintaining the reaction mixture at C. During this addition the emulsion thinned out and globules of tawny-colored oil made their appearance. The pH of the resulting mixture was 8.1.

The mixture of residual emulsion and large oil globules was then treated by adding slowly 121 lbs. of acetic acid (80%). During this addition the pH reading dropped to 5.7 and the residual emulsion broke, precipitating completely the phenyl mercuric acid naphthenate product. To assure attainment of complete equilibrium, the mixture was subjected to 30 minutes of vigorous agitation after the last of the acetic acid was added. After stopping the agitation, a 30 minute period was allowed for coalescence and settling of the oil globules into a clear oil layer. Then, by mechanically draining oif the oil layer, 730 lbs. of product was obtained as a clear oil. The yield on the anhydrous basis was 697 lbs., equivalent to 95.0% yield of acid naphthenate represented by the composition Ph-Hg (naph.).1.25 (H-naph.). Analysis of the product showed 24.3% Hg (anhydrous basis) compared with a theoretical value of 24.4%.

Example 2 i 29.5 grams (0.1 mol) of phenyl mercuric hydroxide were slurried in 400 ml. water at 75-80" C. To this slurry (pH 7.9) was added slowly with good agitation 286 grams (0.120 mol) of naphthenic. acid (equivalentweight 238) to 281 grams water containing 5.0 grams sodium hydroxide. After '10 minutes stirring the suspension had a pH of 9.8. As in Example 1, a heavy oil phase was formed, partly as viscous globules and partly emulsified.

A solution of ammonium naphthenate was next added in the same manner, maintaining the temperature at 75- 80 C. This solution was prepared by adding 25 .0 grams (0.105 mol) naphthenic'acid to 236 grams water to which had been'added 6.6 grams concentrated ammonium hydroxide (28% NH After minutes stirring the suspension showed a pH of 8.6. During this step the viscous globules were converted to a more fluid form.

To the hot mixture of emulsion and separate oil phase was added slowly 15.0 grams'of acetic acid (80%) and the mixture stirred for 10 minutes. The pH at this point was 5.8. During this step the phenyl mercuric acid naphthenate product separated completely as a heavy clear oil layer. After separation from the water layer the oil layer weighed 80.0 grams (77.2 grams anhydrous basis). This compares with a theoretical yield of 81.2 grams for the composition PhHg (naph.).1.25 (H-naph.). The mercury content of the product was 24.4% (anhydrous basis) compared with the theoretical content of 24.6%.

Example 3 33.6 grams (0.1 mol) of phenyl mercuric acetate crystals (technical grade) were slurried in 400 ml. water containing 2.0 grams sodium hydroxide at 7580 C. The slurry pH was 6.2.

A solution of ammonium naphthenate was prepared by dissolving 28.6 grams of naphthenicacid (0.120 mol) in 270 grams water containing 8 grams concentrated ammonium hydroxide. This was added slowly with good agitation to the phenyl mercuric acetate slurry maintained at 7580 C. An oil phase separated as globules in the presence of some emulsion. The pH at this point was 7.5.

A second portion of ammonium naphthenate solution prepared by dissolving 25.0 grams (0.105 mol) naphthenic acid in 236 grams water containing 7 grams concentrated ammonium hydroxide was added. During this addition the oil globules became fluid and a clear oil layer separated in the presence of considerable emulsion. The pH was 7.4.

The mixture was then acidified by the slow addition of 9.5 grams acetic acid (80%) which brought the pH to 6.0. The phenyl mercuric acid naphthenate oil layer,

which was formed by the acidification, was separated from the aqueous layer. Its weight was 77.0 grams (74.9 g. anhydrous basis) compared with a theoretical yield of 81.2 grams, as in Example 2. The mercury analysis gave 25.7% (anhydrous basis).

Example 4 (a) 33.6 grams (0.1 mol) of phenyl mercuric acetate crystals were slurried in 900 ml. water containing 4.8 grams sodium hydroxide. The pH of this slurry was 9.9.

To the suspension maintained at 7580 C. there was added slowly 53.5 grams (0.225 mol) of naphthenic acid. The pH dropped to 8.7 after one-half of the naphthenic acid had been added and to 6.7 when all of it had reacted. The fluidizing effect during the addition of the second half of the naphthenic acid was observed as in the preceding examples.

The mixture was then acidified with 2.0 grams of acetic acid (80% during which the pH dropped to 5.8. After separating from the aqueous layer, the oil weighed 79.0 grams (75.7 g. anhydrous basis) compared with the theoretical yield of 81.2 grams for the composition Ph-Hg (naph.).l.25 (H-naph.). The mercury content was 26.1% (anhydrous basis).

(17) The test in 4a was repeated except that no sodium hydroxide was included in the reaction mixture. After all of the 0.225 mole of naphthenic acid had been added, the pH of the reaction mixture was 2.8. It was not necessary to acidify with acetic acid since the final o1l layer was identical in appearance with that made with alkali. The oilyproduct had a normal weight (81.0 g.) and its mercury content (25.35%, anhydrous basis) was normal.

The water layer was weighed and titrated for its acid content (the reaction product in this layer would be acetic acid). and it contained 5.59 grams acetic acid.

This is practically exactly equal to the acetic acid equiv alent (0.1 mol or 6.00 g.) of the PhHg-acetate taken. Thus this simple analysis proved that all the acetate in the reactant salt was removed as acetic acid and that the hydrogen ions of the latter could only have come from the naphthenic acid used as the other reactant. Since the above refers only to one equivalent of acid, corresponding to formation of the normal PhHg-salt, it follows that the additional 0.125 mol (n=1.25) of naphthenic acid must be incorporated in the oily product in some way or other. Being insoluble, this excess naphthenic acid does not ionize and contribute anything to the acid titration of the aqueous layer.

Example 5 This example illustrates the preparation of phenyl mercuric acid naphthenate with a composition represented by the formula, PhHg(naph.).0.5 (H-naph.).

33.6 grams of phenyl mercuric acetate crystals (0.1 mol) were slurried in 900 m1. of water containing 5.0 grams of sodiumhydroxide at 7580 C. This slurry had a pH of 10.2.

While maintaining the slurry at 75-80 C., 35.7 grams (0.150 mol) of naphthenic acid were added slowly. After a total of 0.125 mol had been added (n=0.25) the fiuidizing effect on the original precipitate of normal phenyl mercuric acetate was observable. The pH showed values of 8.7, 7.4 and 6.7 after successive additions of 0.10, 0.25 and 0.50 mol of naphthenic acid.

The mixture was then acidified with 1.5 grams of acetic acid with a drop of pH to 5.8. The oil layer which formed had an appearance identical to that in Example 4. It weighed 60.25 grams (anhydrous basis) compared to a theoretical yield of 63.3 grams for the composition Ph-Hg(naph. .0.5 (H-naph.)

analysis showed at 32.1% mercury content (anhydrous basis) compared to the theoretical value of 31.55% for this composition.

Example 6 This example illustrates the preparation of tolyl mercury acid naphthenate (in which n=1.1) from tolyl mercuric hydroxide.

30.8 grams tolyl mercuric hydroxide (0.1 mol) were slurried in 900 grams water containing 5.0 grams sodium hydroxide at 75 80 C. (pH 11.5).

50.0 grams naphthenic acid (0.21 mol) were added slowly to the above suspension with observations and pH measurements at three points, viz. after addition of 0.100, 0.025 and 0.085 mol, the corresponding pHs being 11.0, 10.8 and 8.5. The fluidizing effect on the oil globules was noticeable at the total addition of 0.125 mols naphthenic acid (or 1.25 mols per mol of mercury).

Acidification of the suspension with 12.0 grams acetic acid 80%) brought the pH to 5.0, resulting in complete breaking of the emulsion and clarification of the aqueous layer.

The separated oil layer weighed 78.0 g. (77.1 g. anhydrous basis) compared with a theoretical yield of 79.0 grams for the composition The mercury content was 25.3% (anhydrous basis),

equal to the theoretical mercury content in the product of the indicated composition.

Example 7 61.5 grams (0.1 mol) of phenyl mercuric borate powder, (C H Hg) .HBO Y, containing 0.2 equivalent of Hg, were slurried in 1200 ml. water containing 4.8 grams sodium hydroxide. The pH of this slurry was 10.8.

To the suspension maintained at 7580 C. was added slowly 108.8 grams (0.45 mol) of naphthenic acid of equivalent weight 242. The pH dropped to 8.9 when one-half of the naphthenic acid had been added and to 7.6 when all of it had reacted. Most of the product separated as an oil phase, although at this point considerable emulsificatiou in the aqueous phase was apparent.

The mixture was next acidified with 13.0 grams of acetic acid (80%), causing the pH to drop to 5.0. The aqueous layer cleared up slowly and the oil layer appeared normal for a phenyl mercuric acid naphthenate product. After separation from the aqueous layer, the oil weighed 158.0 grams. This compares with a yield of 159.0 grams. when phenyl mercuric acetate is used as reactant in the same equivalent proportions. The mercury content of the phenyl mercuric acid naphthenate product was 24.5% (anhydrous basis) compared with a theoretical value of 24.6%.

Example 8 A slurry containing 33.6 grams of phenyl mercuric acetate crystals (technical) was prepared in 900 ml. of water containing 4.0 grams of sodium hydroxide and heated to 75-80 C. (pH 10.1). To this was added 41.4 grams of oleic acid (0.150 mol) while maintaining the temperature at 75-80" C. The acid oleate, originally precipitated as viscous globules, gradually fluidized and became emulsified, the pH dropping to 7.5.

The mixture was then acidified with 6.0 grams acetic acid (80%) which caused the pH to drop to 4.6, the phenyl mercuric acid oleate product separating as a clear, pale yellow oil. After separating from the aqueous layer, the oil layer weighed 66.3 grams (anhydrous basis), equivalent to a 96.1% yield of phenyl mercuric acid oleate having the composition Ph--Hg(oleate).0.50(H-oleate) The mercury analysis showed 28.7% Hg (anhydrous basis) compared with 29.0%, according to the indicated formula.

Example 9 33.6 grams of phenyl mercuric acetate crystals (0.1 mol) were slurried in 400 grams water containing 2.0 grams sodium hydroxide at 75-80 C. The pH of the slurry was 6.2.

A solution of sodium linoleate was prepared by dissolving 64.3 grams (0.225 mol) of linoleic acid,

C17H31COOH (combining weight 286), in 619 grams water containing 9.3 grams sodium hydroxide. This solution was added with good agitation to the phenyl mercuric acetate slurry maintained at 7580 C. Heavy curds of phenyl mercuric linoleate formed which gradually thinned out and emulsified as the second half of the sodium linoleate solution was added. The pH rose to 9.5 in this step.

Acidification by 17.0 grams acetic acid (80%) then broke the emulsion and gave a good precipitation of an oil layer, the pH going to 5.5. After separation, the oil layer weighed 87.2 grams (anhydrous basis), equivalent to a 95.0% yield of phenyl mercuric linoleate having the the composition Ph-Hg (linol.).1.25 (H-linol.). Analysis showed a mercury content of 21.5% (anhydrous basis) compared with 21.75% theoretical mercury in the composition indicated.

10 Example 10 33.6 grams of phenyl mercuric acetate crystals (0.1 mol) were slurried in 400 grams Water containing 2.0 grams sodium hydroxide at 8590 C., giving a pH of 6.3. v

A solution of sodium tallate was prepared by dissolving 34.6 grams (0.120 mol) of distilled tall oil in 332 grams water containing 5.0 grams sodium hydroxide. The sample of tall oil used contained 66.2% fatty acids, 32.0% rosin acids and 1.8% unsaponifiables. The composition of the fatty acids component was 44.0% linoleic, 51.0% oleic and 5.0% saturated acids. This solution was run slowly into the slurry of phenyl mercuric acetate maintained at 85-90 C., the pH rising to 9.8.

A solution of ammonium tallate was prepared by dissolving 30.2 grams (0.105 mol) of the same tall oil in dilute ammonium hydroxide made by diluting 8.0 grams concentrated ammonium hydroxide (28% NH,) with 602 grams water. This solution was then added slowly to the reaction mixture at 85-90 -C. The precipitate became emulsified with some separate oil layer and the pH dropped to 8.1.

The mixture was next acidified with 14.0 grams acetic acid which brought the pH to 5.3. The oil layer which precipitated, after being separated from the aqueous layer, weighed 85.7 grams (anhydrous basis), equivalent to a 92.8% yield of phenyl mercuric acid tallate represented by the composition PhHg (tallate).1.25 (H-tallate). The mercury content was 21.6% (anhydrous basis) compared with the theoretical mercury content of 21.65% in the indicated formula.

Example 11 A slurry of phenyl mercuric acetate was prepared as in Example 10 with a pH of 6.1. Two stearate soap solutions were then made up as follows from triple pressed stearic acid powder.

Sodium stearate-34.1 grams (0.120 mol) of stearic acid powder were dissolved by stirring into 697 grams water containing 5.0 grams sodium hydroxide at 75-80" C.

Ammonium stearate-29.8 grams (0.105 mol) of stearic acid powder were dissolved by stirring into 594 grams water containing 8.0 grams concentrated ammonium hydroxide (28% NH at 7580 C.

The slurry of phenyl mercuric acetate was then heated to -90" C. and the sodium stearate solution was added slowly to it. The pH rose to 9.4 during the precipitation of a whitish oil on the beaker walls and partial formation of an emulsion. The ammonium stearate'solution was then added, maintaining the temperature at 85-90 C. During this addition the oil thinned out and emulsified completely and the pH dropped to 8.0.

Slow addition of 22.0 grams acetic acid (80%) to the emulsion caused formation of an oil layer and the pH dropped to 5.0. After separating the oil layer, it was allowed to cool by standing some hours, during which it solidified to a cake weighing 91.8 grams (anhydrous basis). This is equal to the theoretical yield for 0.1 mol of the composition of PhHg (stear.).1.25 (H stean). The mercury content was 21.3% (anhydrous basis) compared with the theoretical mercury content of 21.8% in the indicated formula.

Example 12 This example illustrates the preparation of tolyl mercuric acid oleate from tolyl mercuric hydroxide.

30.8 grams tolyl mercuric hydroxide (0.1 mol) were slurried in 900 grams water containing 5.0 grams sodium hydroxide at 7580 C. (pH 10.7).

58.0 grams of oleic acid (0.21 mol) were added slowly to the above suspension, forming viscous oil globules which thinned out to an emulsion when 0.125 mol of the 11 acid had been added. The pH was 9.6 after addition of the full amountof oleic acid.

Acidification with 23.5 grams acetic acid (80%) brought the pH to 4.5, resulting in breaking of the emulsion and formation of clear oil and water layers.

After separating from the water layer, the oil layer Weighed 82.5 grams (anhydrous basis), equivalent to a 94.8% yield of tolyl mercuric acid oleate of the comosition CH C H 'Hg (oleate).l.l (H-oleate). The mercury content was 23.1% (anhydrous basis) compared with the theoretical value of 23.0% in the indicated formula.

We claim:

1. A composition having the formula in which AI is an aryl group; Hg is mercury; A is the anion of a weak monobasic acid selected from the group consisting of naphthenic acid, fatty acids containing between about 8 and 18 carbon atoms, and mixtures of such acids; n is greater than 0.2; and H is hydrogen.

2. The composition of claim 1 in which Ar is phenyl.

3. The composition of claim 1 in which Ar is tolyl.

4. The method of attacking micro-organisms which comprises subjecting them to the product of claim 1.

5. The method of attacking micro-organisms which comprises subjecting them to a dispersion containing a mixture of a dispersing agent and the product of claim 1.

6. A composition containing aryl mercury acid naphthen'ate and having the formula in which Ar is an aryl group; Hg is mercury; A is the anion of naphthenic acid; n is greater than 0.2; and H is hydrogen.

7. An aryl mercury acid naphthenate having one equivalent of naphthenic acid linked to the normal aryl mercuric naphthenate.

8. A composition of an aryl mercury acid salt of a fatty acid having the formula in which Ar is an aryl group; Hg is mercury; A is the anion of a weak monobasic acid selected from the group consisting of fatty acids containing between about 8 and 18 carbon atoms, and mixtures of such acids; 11 is greater than 0.2; and H is hydrogen.

9. The composition of claim 8 in which A is the anion of ol'eic acid.

10. The composition of claim 8 in which A is the anion 'of linoleic acid.

11. The composition of claim 8 in which A is the anion of fatty acids derived from tall oil.

12. The method of preparing an anti-micro-organismal agent that is readily dispersible in water and oil systems and which embodies an aryl mercury acid salt of an acid selected from the group consisting of naphthenic acid, fatty acids, and mixtures of such acids, which method comprises mixing an aryl mercury compound with more than 1.2 equivalents of a compound selected from the group consisting of naphthenic acid, sodium naphthenate, potassium naphthenate, ammonium naphthenate, fatty acids containing between about 8 and 18 carbon atoms, sodium salts of such fatty acids, potassium salts of such fatty acids, ammonium salts of such fatty acids, and mixtures of such compounds; adjusting the acid concentration of said mixture to between about pH 7 and pH 3; and mechanically separating the resultant oily layer of said anti-micro-organismal agent from said mixture.

13. The method of preparing an anti-micro-organismal agent that is readily dispersible in water and oil systems and which embodies an aryl mercury acid salt of an acid selected from the group consisting of naphthenic acid, fatty acids, and mixtures of such acids, which method comprises preparing an aqueous slurry of an aryl mercury compound that is at least slightly water soluble, mixing said slurry with more than 1.2 equivalents of a compound selected from the group consisting of naphthenic acid, sodium naphtheuate, potassium naphthenate, ammonium naphthenate, fatty acids containing between about 8 and 18 carbon atoms, sodium salts of such fatty acids, potassium salts of such fatty acids, ammonium salts of such fatty acids, and mixtures of such compounds; agitating the mixture; adjusting the acid concentration of said We to between about pH 7 and pH 3 to form an oily layer; and mechanically separating the resultant oily layer of said anti-micro-organismal agent from said mixture.

14. The method of claim 13 in which a base is included in the mixture to maintain the pH above 6 prior to adjustment of the acid concentration to between about pH 7 and pH 3.

15. The method of claim 13 in which said mixture is agitated at a temperature of between about 60 C. and C., and said pH is thereafter adjusted to between about pH 7 and pH 3 by addition of acetic acid.

16. The method of claim 13 in which said aryl mercury compound is more than 0.01% soluble in water.

17. The method of preparing an anti-micro-organismal agent that is readily dispersible in water and oil systems and which embodies an aryl mercury acid salt of an acid selected from the group consisting of naphthenic acid, fatty acids, and mixtures of such acids, which method comprises mixing an aryl mercury compound that is at least 0.1% water soluble with water to form an aqueous slurry of such compound, adding sutficient base to raise the pH of the slurry to above pH 6, heating the slurry to a temperature between 60 C. and 100 (3., adding to the slurry more than 1.2 equivalents of a compound selected from the group consisting of naphthenic acid, sodium naphthenate, potassium naphthenate, ammonium naphthenate, fatty acids containing between about 8 and 18 carbon atoms, sodium salts of such fatty acids, potassium salts of such fatty acids, ammonium salts of such fatty acids, and mixtures of any of such compounds; agitating the mixture; adjusting the acid concentration of said mixture to between about pH 7 and pH 3 by addition of a weak organic acid to form a distinct oily layer of the reaction product; and mechanically separating the resultant oily layer of said anti-micro-organismal agent from said mixture.

18. A composition containing aryl mercury acid naphthenate and having the formula in which Ar is a phenyl radical; Hg is mercury; A is the anion of naphthenic acid; 11 is greater than 0.2; and H is hydrogen.

19. The method of preparing an anti-micro-organismal agent that is readily dispersible in water and oil systems and which embodies a phenyl mercury acid salt of naphthenic acid, which method comprises preparing an aqueous slurry of a phenyl mercury compound that is at least slightly water soluble, mixing said slurry with more than 1.2 equivalents of naphthenic acid; agitating the mixture; adjusting the acid concentration of said mixture to between about pH 7 and pH 3 to form an oily layer; and mechanically separating the resultant oily layer of said antimicro-organismal agent from said mixture.

References Cited in the file of this patent UNITED STATES PATENTS Engelmann et a1. Mar. 12, 1935 Sowa Aug. 16, 1949 y Agents, Nat. Paint Var. Assoc., 1947, Giro. 719 (13 pp.). 

1. A COMPOSITION HAVING THE FORMULA 